This application claims priority to Japanese patent application serial number 2002-032816, the contents of which are incorporated herein by reference.
The present invention relates to gas/liquid separating devices that include a gas/liquid separator and a liquid drain. More preferably, the present invention relates to gas/liquid separating devices that include a bypass path for reducing pressure within the liquid drain.
A vertical cross sectional view of a known gas/liquid separating device is shown in FIG. 3. The gas/liquid separating device includes a gas/liquid separator 101 and a liquid drain 102. The gas/liquid separator 101 includes a substantially cylindrical cyclone generator 110, in which a cyclone chamber 112 is defined. A gas/liquid inlet port 113 is formed on an upper lateral side of the cyclone generator 110 and is oriented in a substantially tangential direction of the cyclone generator 110. A liquid outlet port 114 is formed on the bottom of the cyclone generator 110 and extends downward therefrom. A gas channel 118 extends from the top of the cyclone generator 110 and extends upward therefrom.
A mixed gas/liquid flow M that will be separated by the gas/liquid separator 101 may be supplied into the cyclone chamber 112 via the inlet port 113 under relatively high pressure in the tangential direction of the cyclone generator 110. The mixed gas/liquid flow M may contain a gas (e.g., hydrogen gas) and relatively small liquid particles (e.g., water particles). The mixed flow M may circulate or swirl, so that the mixed flow M may be separated into the liquid and the gas due to centrifugal force. The separated liquid may flow downwardly into a float chamber 130 defined within the liquid drain 102 via the liquid outlet port 114 of the cyclone generator 110 and then may be discharged to the outside. On the other hand, the separated gas may be discharged from the cyclone generator 110 into the gas discharge channel 118.
The liquid drain 102 includes a drain body 120, a valve seat 134, a float valve 136 and a float 140. The float chamber 130 is defined within the drain body 120. A liquid inlet port 131 is formed on the drain body 120. One end of the liquid inlet port 131 opens within the upper space of the float chamber 130 and the other end of the liquid inlet port 131 communicates with the liquid outlet port 114 of the separator 101. Therefore, the separated liquid may flow downward from the liquid outlet port 114 through the liquid inlet port 131 and then may be stored in the float chamber 130.
The valve seat 134 defines a drain hole 135 and the liquid stored in the float chamber 130 can be discharged through the drain hole 135. In addition, a liquid discharge channel 133 extends from the drain body 120. One end of the liquid discharge channel 133 communicates with the drain hole 135 and the other end of the discharge liquid channel 133 communicates with the atmosphere. A check valve 132 is disposed within the discharge liquid channel 133 in order to prevent liquid counter flow. The float valve 136 may be designed as a needle valve and may be vertically movably disposed within the valve sheet 134. The float valve 136 may open and close the drain hole 135 as the float valve 36 respectively moves upward and downward.
A float 140 may include a float lever 141 that can move together with a float body 142. The float 140 may float on the surface of the liquid stored within the float chamber 130. The float lever 141 is pivotally mounted on an inner wall of the drain body 120 by means of a pin 145, so that the float body 142 can vertically pivot about the pin 145. The float lever 141 is coupled to the float valve 136, so the float valve 136 will move vertically as the float lever 141 pivots.
When the level of the liquid stored in the float chamber 130 becomes higher than a predetermined level, the. float body 142 moves upward. Then, the float valve 136 moves upward in response to the movement of the float lever 141, so that the float valve 136 opens the drain hole 135. Therefore, the liquid within the float chamber 130 is discharged to the outside through the liquid discharge channel 133 via the drain hole 135, so that the water level is lowered. As the liquid level in the float chamber 130 is lowered, the float body 142 moves downward. Then, the float valve 136 moves downward in response to the movement of the float lever 141. When the water level reaches the predetermined level, the float valve 136 closes the drain hole 135. Therefore, further discharge of the liquid within the float chamber 130 is stopped.
As a result, the liquid drain 102 serves to discharge the liquid within the float chamber 130 when the liquid level exceeds the predetermined level, so that the amount of water within the float chamber 130 may be maintained at a predetermined amount.
However, when the gas and liquid are separated using this known gas/liquid separating device, a possibility exists that liquid particles may be entrained by the gas that flows from the cyclone chamber 112 of the separator 101 into the gas discharge channel 118. As a result, the liquid particles may be carried into the gas discharge channel 118. For example, this phenomenon may occur when the float valve 136 of the liquid drain 102 closes the drain hole 135, and when (1) a relatively large amount of liquid flows from the upstream side to block the liquid inlet port 131 and to thereby prevent the liquid from easily flowing into the float chamber 130 via the liquid inlet port 131 or (2) the mixed gas/liquid flow M is circulating within the cyclone 112 at a relatively high speed.
When the float valve 136 of the liquid drain 102 opens the drain hole 135, the liquid and the gas within the cyclone chamber 112 may smoothly flow into the float chamber 130. Therefore, in this occasion, there is a reduced possibility that water will be carried into the gas discharge channel 118. However, if the float valve 136 is closed, the space within the float chamber 130 may be blocked in a manner like a blind alley. Therefore, the gas within the float chamber 130 may not be easily exchanged with the liquid that may fall into the float chamber 130 from the upper side of the float chamber 130. As a result, the liquid within the cyclone chamber 112 may stagnate within the liquid outlet port 114. When this stagnation occurs, the liquid will likely be entrained by the gas that flows into the gas discharge channel 118.
Therefore, the known gas/liquid separating device has a problem that the liquid particles may enter into the gas discharge channel 118 due to entrainment by the gas that flows from the cyclone chamber 112 of the gas/liquid separator 101 into the gas discharge channel 118. As a result, liquid can not be effectively separated from the gas. In addition, when the liquid enters the gas discharge channel 118, the liquid may be unfavorably retained in the gas discharge channel 118.
It is, accordingly, one object of the present invention to teach improved techniques for preventing or substantially minimizing liquid from being carried into a gas discharge channel.
According to one aspect of the present teachings, gas/liquid separating devices are taught that may include a separator for separating a mixed gas/liquid flow, e.g. a mixed flow of hydrogen gas and water. A liquid drain may be coupled to the separator and may define a liquid storage chamber. In this case, liquid separated by the separator may flow into the liquid storage chamber, e.g., due to gravity. The liquid may be temporarily stored within the liquid storage chamber and may be discharged from the liquid drain at an appropriate time before the liquid fully occupies or completely fills the liquid storage chamber. Therefore, a space that is not occupied by the liquid is ensured within the liquid storage chamber. An adjusting device may be utilized to adjust the pressure within the space of the liquid storage chamber. For example, the adjusting device may adjust the pressure so that the separated liquid can easily flow into the liquid storage chamber.
Therefore, the separated liquid may be prevented, or substantially prevented, from being entrained by the separated gas that is discharged from the separator. As a result, the liquid separation efficiency of the separator may be improved.
According to another aspect of the present teachings, the adjusting device may enable gas that has entered into the liquid storage chamber to be communicated, e.g., to a gas discharge port or gas discharge channel, thereby reducing the pressure within the liquid storage chamber. As a result, the separated liquid may easily enter the liquid storage chamber without being blocked or prevented from entering the liquid storage chamber by relatively high pressure within the liquid storage chamber.
According to another aspect of the present teachings, the adjusting device may include a pipe that is connected between the space of the liquid storage chamber and a source of negative or reduced pressure. For example, the source of negative or reduced pressure may include a gas discharge channel that communicates with the separator in order to discharge the separated gas to the outside. Therefore, the flow of the separated gas may be used to generate a negative or reduced pressure within the pipe. Thus, manufacturing costs may be minimized because no additional device is required to be dedicated to generate the negative or reduced pressure.
According to another aspect of the present teachings, the pipe may connect the space of the liquid storage chamber to the gas discharge channel and may bypass a gas/liquid separation chamber defined within the separator. According to another aspect of the present teachings, a first end of the pipe may open into the gas discharge channel within an angular range of about 0 degree to 90 degrees relative to the direction of flow of the separated gas within the gas discharge channel. By utilizing this arrangement, negative or reduced pressure can be effectively generated. For example, the first end of the pipe may open into the gas discharge chamber substantially perpendicular to the direction of flow of the separated gas within the gas discharge channel. This arrangement may be suitably incorporated in combination with the arrangement in which the pipe is disposed outside of the separator.
In the alternative, the first end of the pipe may open into the gas discharge chamber in substantially the same direction as the direction of flow of the separated gas within the gas discharge channel. This arrangement may be suitably incorporated in combination with the arrangement in which the pipe is disposed within the separator, e.g., through the separation chamber of the separator and the liquid storage chamber of the liquid drain. According to this arrangement, the pipe will not be exposed to the outside of the gas/liquid separating device. Therefore, the gas/liquid separating device may have a relatively compact construction.
In another aspect of the present teachings, an orifice may be disposed adjacent to and upstream of a converging point of the pipe to the gas discharge channel. As the separated gas flows through the orifice, the flow rate (speed) of the gas may be increased in order to increase the negative or reduced pressure at the converging point of the pipe. Therefore, the gas within the liquid storage chamber may be rapidly and reliably discharged into the gas discharge channel via the pipe. As a result, separation efficiency may be further improved. For example, the orifice may include a constriction opening that has a smaller cross section than the cross section of the gas discharge channel.